1. Field of the Invention
The present invention relates to vehicles that have generators mounted therein. More particularly, the present invention relates to safety systems for assuring a proper operation of the generator of the vehicle. More particularly, the present invention relates to safety systems for assuring that the generator is turned off when certain conditions occur.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98
Various vehicles have been developed that include generators that are operated independently of the vehicle engine. Typically, these generators will supply an independent source of alternating current so as to operate equipment within the vehicle. It is known that certain trucks, recreational vehicles and emergency medical vehicles include generators. In certain trucks, these generators are utilized so as to maintain a cooling condition within the cab or bed of the truck. In other circumstances, generators are used on recreational vehicles so as to supply power to various appliances located within the recreational vehicle.
Relatively recently, generators have been utilized in association with mobile emergency vehicles. Such mobile emergency vehicles are currently manufactured by Frazer, Ltd. of Houston, Tex. These mobile emergency vehicles are presently the subject of U.S. Pat. No. 4,672,296 (issued on Jun. 9, 1987) and U.S. Pat. No. 4,785,227 (issued on Nov. 15, 1988) to J. Griffin. In particular, each of these mobile emergency vehicles are unique in that it incorporates a generator that is mounted on a skid-type of mounting frame and fitted within the compartment of the mobile emergency vehicle. The emergency medical vehicle is built on a conventional truck chassis and has the main transport engine located beneath the hood in a manner well-known in the art. The patient compartment is mounted on the rearward portion of the truck chassis in a manner that is also known in the prior art. The mobile emergency vehicle of these prior art patents has the vehicle essentially self-supported with regard to its electrical requirements. An auxiliary engine and generator are mounted exteriorly of the patient module such that the exhaust system extends outwardly so as to deliver minimal noise and vibration to the patient module. The electrical output of the generator is preferably capable of providing 4 to 6 kW of continuous electrical power and is capable of continuously delivering 115 volts of AC power to the electrical load center of the patient compartment. The load center provides distribution of the primary output of the generator to air-conditioning and heating. As such, the generator provides the power necessary to supply both cooling and heating to the patient compartment. The generator is preferably located on the passenger side at a rear lower corner of the vehicle. The generator provides power for emergency lights, air conditioning, heating, suction, interior lights, and the like.
Prior to the development of the emergency medical vehicle of Frazer, Ltd., all of the power requirements for ambulances were achieved through the use of an alternator directly connected to the engine. As such, the power to the patient compartment had to be supplied from energy stored in the battery or directly by an alternator. Typically, during procedures, the engine would remain idling so as to continuously supply power. Unfortunately, the power supplied by the alternator is a relatively poor quality of power. There are substantial fluctuations in the power levels provided by such alternators. Additionally, the exhaust from the idling engine would be discharged in the area of the double doors located at the rear of the patient compartment. As such, emergency medical personnel and patients would be exposed to substantial amounts of carbon monoxide when the patient is being placed into the interior of the patient compartment. Under other circumstances, the emergency vehicle would enter a closed area with the engine running. As such, there would always remain the danger of carbon monoxide poisoning during those events in which the engine is maintained in an idling mode for the purposes of supplying power.
Engines, including generators, produce exhaust gases containing carbon monoxide as result of the incomplete combustion of carbon-based fuels. As is well known, carbon monoxide is a very poisonous gas. The presence of carbon monoxide in one's bloodstream reduces the level of oxygen in the blood, which in turn, starves the brain of oxygen. The lethal effect of carbon monoxide poisoning has been known since ancient times. Unfortunately, carbon monoxide is particularly dangerous because it is both colorless, tasteless and odorless. This makes detection of the gas by human senses difficult.
Numerous carbon monoxide poisonings occur each year. Carbon monoxide poisoning results from voluntary or involuntary inhalation of exhaust gases. Many systems are presently available for monitoring levels of carbon monoxide. However, present systems fail to solve several problems associated with detecting hazardous concentrations of carbon monoxide produced by a vehicle. Present carbon monoxide monitoring and detection systems inform the vehicle operator of potentially dangerous levels of carbon monoxide. The systems, however, do not alleviate the problem by disabling the source of the noxious gas. Therefore, the risk of carbon monoxide poisoning continues after detection of the hazardous condition.
Importantly, the disabling of the source of carbon monoxide upon detection of a hazardous concentration of the gas may often cause false disablements. Often, the concentration of carbon monoxide is hazardous at a specific but short time and the carbon monoxide quickly dissipates. In these situations, disabling the source is unnecessary to the safety of the vehicle's operators and passengers and is a nuisance to the vehicle operator.
Disabling a vehicle's engine or generator upon detection of a hazardous level of carbon monoxide is also dangerous. This is particularly true in the case of emergency medical vehicles. The emergency medical vehicles are required to transport a patient in a quick and efficient manner. If the vehicle is disabled for any period of time, then this can be hazardous to the well-being of the patient.
Alarms are available that provide visual and audio information when carbon monoxide levels reach an undesirable level. However, vehicle operators may be tempted to disable the alarm in order to avoid the annoying sound. Whenever the alarm is disabled, a very dangerous condition can occur. Other vehicle operators may not know of the disabled alarm.
In those cases where the emergency medical vehicle utilizes a generator to power the patient compartment, it will be undesirable to use the quiet generator when the engine of the vehicle is not running Under the circumstances, the generator will produce carbon monoxide. This carbon monoxide gas will be discharged at the rear of the vehicle. This is the area in which the patient-loading activities will occur. As such, exposure to the carbon monoxide gas can occur in such areas. Additionally, the operators of the emergency medical vehicle may be unaware of the operation of the generator because the generator is so quiet carbon monoxide exposure could occur inadvertently. However, under certain circumstances, it is desirable to run the generator while the engine is off. For example, operators of emergency medical vehicles at a sporting event may wish to use the generator to power heating or air-conditioning while the engine is turned off. As such, it is desireable to allow the operators the opportunity to use the generator while the engine is off.
Whenever the emergency medical vehicle is at a station, it will be connected to a shore line at the station. The shore line will provide AC power to the vehicle. As such, there would never be a need to use the carbon monoxide-producing generator while at the station. As such, a need has developed whereby a system can be developed that effectively prevents carbon monoxide poisoning and which controls the operation of the generator in order to prevent such poisoning.
In the past, various patents have issued relating to control systems for generators which serve to control the operation of the generator in response to carbon monoxide levels. For example, U.S. Pat. No. 5,333,703, issued on Aug. 2, 1994 to James et al., describes a carbon monoxide sensor and control for motor vehicles. The system monitors carbon monoxide levels produced by the operation of the engine of a vehicle. The system includes a detector in the vehicle's passenger compartment for detecting the concentration of carbon monoxide within the compartment and circuitry for generating a high carbon monoxide signal when the detected concentration of carbon monoxide inside the compartment is greater than a predetermined level. The system disables the operation of the engine in response to the high carbon monoxide system. The system also senses a status condition of the vehicle and inhibits the disabling of the engine when the status condition is sensed.
U.S. Pat. No. 6,983,726, issued on Jan. 10, 2006 to Luo et al., describes a method for monitoring and mitigating exhaust gas emitted from a vehicle. A remote monitoring device within a closed structure is trained in response to a training signal transmitted from a remote transmitter device. A remote engine start signal is intercepted within a receiving circuit of the remote monitoring device during an actual remote engine start operation. The exhaust gas emitted from the vehicle is monitored in response to receiving the remote engine start signal. A determination is made if an exhaust gas concentration level is greater than a predetermined threshold. A control signal is transmitted to a mitigation device for mitigating the exhaust gas within the closed structure when the exhaust gas concentration is greater than the predetermined level.
U.S. Pat. No. 8,534,258, issued on Sep. 17, 2013 to M. Cristfro, describes a carbon generator and carbon monoxide detector. The generator includes an internal combustion engine coupled to the generator. The internal combustion engine produces exhaust gases when operating. The system includes a gas detector positioned in an enclosure into which exhaust gas may flow. The detector is coupled to a signal transmitter that is operable to send a signal of a predetermined level when a selected gas or compound is sensed. The signal is received by an engine shutdown device that is operable to shut down engine operation after the signal is received.
United States Patent Publication No. 2007/085692, published on Apr. 19, 2007 to Grant et al., teaches a carbon monoxide detector on a gas-powered generator. The carbon monoxide detector is coupled to the generator. The detector is configured to provide notification when a predetermined concentration of carbon monoxide is reached. The detector is configured so as to disable the generator.
U.S. Patent Publication No. 2012/0130604, published on May 24, 2012 to Kirshon et al., provides an automatic shutdown system for automobiles. A vehicle status monitor and control system monitors a series of sensors installed within a vehicle to monitor specific functions to determine if a vehicle engine is running and there is a potential for toxic exhaust gases to accumulate so as to create a toxic environment. The vehicle status monitor and control system determines if the vehicle is running and stationary over a period of time. The system additionally monitors the presence of a driver. If the predetermined conditions are met, the system terminates the operation of the vehicle's engine. The system can optionally include an override feature to ensure the engine continues running when desired.
It is an object of the present invention to provide a safety system that reduces the risk of carbon monoxide poisoning.
It is another object of the present invention to provide a safety system that assures that the generator will not start under certain conditions.
It is another object of the present invention to provide a safety system that assures that the operator must acknowledge certain circumstances when the generator is running.
It is another object of the present invention to provide a safety system that avoids dangerous situations.
It is still another object of the present invention provide a safety system that requires the operator to be proactive when unsafe conditions are recognized.
It is a further object of the present invention provide a safety system that minimizes the ability to damage or tamper with the alarm equipment.
It is still a further object of the present invention to provide a safety system that enhances safety.
These and other objects and advantages of the present invention will become apparent from a reading of the attached specification and appended claims.